A multiplicity of technologies can be used for wireless data transmission. Mobile radio networks are operated using, for instance, the GSM (Global System for Mobile communications) or UMTS (Universal Mobile Telecommunications System) standard and wireless local area networks (WLAN) are operated using, for example, the IEEE (Institute of Electrical and Electronics Engineers) 802.11, HiperLAN (High-Performance LAN), or Bluetooth standard.
For full-coverage provisioning of mobile radio users, for instance mobile telephones or portable computers having a corresponding radio transmission device, it is possible to use mobile radio networks conforming to, for example, the GSM or UMTS standard. WLANs can be used for supplementing in what are termed hot spots, which is to say small, local areas having a high user density, such as airports or hotels.
The provider of a service in a radio communication system can be either the operator of the radio communication system or another service provider who, by way of suitable agreements, is allowed to access the radio communication system's infrastructure.
A service offered in a radio communication system can thus possibly be used by a mobile radio user via different service providers. Depending on what specific requirements the mobile radio user places on the desired service in terms, for example, of price or quality of data transmission, an alternative provider may in each case offer the mobile radio user the best conditions.
A method is known from WO 02/32181 A1 whereby a mobile station requests and receives a program from an operator of a radio communication system who is active in a first country. With the aid of said program a more favorably priced operator of a radio communication system in a second country can be selected for the mobile station. When a telecommunication service in the second country is requested, via a radio communication system of the second country the program controls a process of communicating with an accessibility assistant connected to the radio communication system of the first country. From the accessibility assistant the mobile station obtains a list of operators of radio communication systems in the second country along with information about said operators' prices. Either the mobile station user can then select one of the operators him- or herself or the program will automatically select the most favorable operator for the requested telecommunication service.